if some of ur rogue skills
never crit, u need to make a bug report cause probably its r/k-based bug. there is a similar one for r/d where the skill poison shroud
never crits.
in case u just have lower crit than expected compared to ur knights skill, maybe should provide some feedback on ur performance on other instances too. does it happen only in PoM or is a general issue of ur character?
besides that, maybe the old bug of Holly Strike has returned

u see, k/r has a skill that makes holy strike crit for extra 40% (not sure about the percentage). well, the bug was that this % chance was carried over even if u were r/k too. they had fixed it at some patch ago, but probably has re-appeared. so, is it only ur HS skill that cits endlessly or disarmament too for example?